Nisoxetine hydrochloride

Potent and selective inhibitor of the norepinephrine transporter

Nisoxetine hydrochloride is a selective norepinephrine reuptake inhibitor (NRI). It is primarily used in research rather than as an approved therapeutic drug.

Key Pharmacological Actions

1. Selective inhibition of norepinephrine reuptake

• Nisoxetine blocks the norepinephrine transporter (NET) on presynaptic neurons.

• This increases norepinephrine levels in the synaptic cleft.

• Enhances noradrenergic signaling in the brain and peripheral nervous system.

2. High selectivity

• It has minimal effect on serotonin (SERT) and dopamine (DAT) reuptake systems compared to its strong action on NET.

• Because of this selectivity, it is often used in experiments to differentiate NET function from other monoamine systems.

3. Research applications
Nisoxetine is commonly used to:

• Study NET density and distribution via radiolabeled derivatives.

• Investigate noradrenergic involvement in mood regulation, attention, pain perception, and autonomic function.

• Characterize pharmacodynamics of antidepressants that target norepinephrine.

4. Not approved for clinical use

• Despite being developed as an antidepressant candidate, it was never marketed.

• Its role is largely preclinical and experimental.

+4C

1) Torres, G.E., Gainetdinov, R.R., and Caron, M.G. Plasma membrane monoamine transporters: Structure, regulation and function. Nat. Rev. Neurosci. 4(1), 13-25 (2003).

2) Tyler, T.D., and Tessel, R.E. Amphetamine’s locomotor-stimulant and noreprinephrine-releasing effects: Evidence for selective antagonism by nisoxetine. Psychopharmacology (Berl) 64(3), 291-296 (1979).